A patent document listed below discloses a burring apparatus for use with a friction welding machine equipped with: a spindle unit, mounted on the machine table of the friction welding machine and accommodating a main spindle having a rotary chuck for gripping a first work piece; a slide having a fixed chuck for gripping a second work piece coaxially with a first work piece and movable in the axial direction of the main spindle; a pair of cutter arms arranged on the slide to constitute a rotatable annular cutter that surrounds the work pieces; and a slide unit (“auxiliary member” facilitating burring operation) mounted on the slide to support the end of the second work portion of the welded pieces (hereinafter referred to as jointed work piece) and slidably in the axial direction of the welded work pieces.
Specifically, the welding machine is adapted to friction weld the two work pieces by moving the slide towards the spindle unit to thereby press one end of the second work piece onto one end of the first work piece in rotation, and, after the welding, adapted to loosen the chuck of the main spindle holding the welded (jointed) piece and withdraw the first piece end of the jointed work piece from the main spindle by retracting the slide by a predetermined length. Then the cutter arm is rotated to form an annular cutter round the jointed work piece subsequently, the fixed chuck (holding the jointed work piece) is loosened and the slide is retracted backward together with the slide unit (auxiliary member) until the rear legs of the slide unit (auxiliary member) abuts against the metal stopper formed on the machine table of the welding machine to stop the slide unit (auxiliary member), thereby allowing only the slide to go backward. Thus, as the slide is retracted backward, the jointed work piece is forced forward by the slide unit (auxiliary member) with respect to the annular cutter and fixed chuck, thereby causing the blur formed round the welded portion of the jointed work piece to be sheared by the annular cutter. Hence, the burr is automatically removed in a welding cycle.